Train control



July 24, 192s. 1,678,615

' W. K. VHOMIE ETAL TRAIN CONTROL v n rWigman-Filed July 26,*'1925 2 sheets-sheet 1 Flai.

mo. enroule July 24, 192s. 1,678,615

w.. K. HowE ET Al.

TRAIN coNTRoL original Filed July 26, 192s 2 sheets-sheet 2 FIQB. l i il# Con.ReL and 1nd. Group.

To Equal (ging Reservo r. m9@

Patented July 24, 1928.

UNITED STATES i 1,678,615 PATENT OFFICE..A

WINTHROP IK. HOWE AND CHARLES S. BUSHNELL,

OF ROCHESTER, NEW YORK, .AS-

SIGNORS '10 GENERAL RAILWAY SIGNAL COMPANY, 0F ROCHESTER, NEW YORK.

TRAIN CONTROL.

Original application nled .iTuly 26, 1923, Serial No. 653,898.. Divided and this application nled Hay 25,

1925. Serial No. 32,865.

This invention relates to train control systems designed to give full protection under the varying operation conditions encountered in practice.

5 In accordance with this invention, it is proposed to communicate or transmit the desired controlling influences from the trackway to the moving trains by a means o f the inductive non-physical contact type which 1s l0 continuously effective and affords what is conveniently termed continuous inductive control; impose upon the' train at all times predetermined speed restrictions wh-ich are automatically varied in accordance with traiiic conditions and the location of the train so as to be adequate for safety and at the same time suitable for providing a high degree of facility of train movement, due allowance being made for the variable lengths of blocks commonly encountered in practice; to permit the engineer under automatically imposed restrictions to manually cut out or render ineii'ective -the automatic control of the train while traveling in unequipped or non-signalled territory, a distinctive indication in the cab signifying that the train is traveling without protection being continuously displayed while the train is in such unsignalled territory; and the automatic control being automatically restored as soon as the train again comes into equipped or signalled territory; to give at times cab signal indications which correctly show the existing traiiic conditions ahead, whether clear or caution, these cab signal indications being automatically changed instantly as the traiic conditions become more favorable; to give the engineer a reliable warning signal prior to every automatic brake application, if desired, so as to facilitate handling of the train by the engineer safely and with the least delay; to provide a suitable penalty for failure on the part -of the engineer to govern his train properly 4in'paccordance with the information provided; to make provision for manual adjustment of the apparatus on the locomotive or other vehicle so that it'may be used in either freight or passenger service as de- Asired; and in general make adequate provision for the various features of automatic, manual, and combined automatic and manual control needed to satisfy the varying and l, peculiar requirements of an automatic train also illustrates conventionally the receiving and amplifying apparatus of the car-carried apparatus including a three-position main control relay;

gig. 2 shows a side elevation of the cam an governor contacts for freight service,

wherein the contacts may be maintainedclosed independently of the cam and governor mechanism; and

Fig. 3 illustrates car-carried apparatus embodying the present invention wherein an automatic application of the brakes may be prevented by the engineer if he anticipates the automatic application of the brakes by a manual application.

This application is a division of the prior application of W. K; Howe and C. S. Bushnell iiled July 26, 1923, Ser. No. 653,898.

Generally speaking, in practicing the presen t invention, alternating current is transmitted down one of the track rails through the usual track relay (or the axles of a train, if the block happens to be occupied) and back through the other rail, this current corresponding to the usual track circuit current and conveniently referred to as loop circuit current; and another alternating current, preferably of the same frequency but displaced in phase `as much as possible from the first mentioned current is transmitted through said two track rails in multiple and back over a return wire, this other current being called the simplex circuit current. These currents in the track rails are detected .or picked up on the car by magnetic induction, amplified, and then used to control a suitable two-element or polyphase alternating current relay. These currents in the track rails are controlled by the usual track circuits so that their existence and phase relation in any given block depends upon the proximity of a train ahead. The

corresponding loop circuit current and the simplex circuit current in the track rails are separately detected or picked up by suitable receiving devices on the vehicle, amplified, and then used to control a two-element or polyphase alternating current relay or equivalent electro-responsive device. This relay governs the cab signal indications, the speed governed brake control apparatus, and the other devices on the car used in attaining the resuits contemplated by this invent-ion.

Inyuemce cofnimuaz'catt'ag means.

Tmclcway eguz'pfment.-A.s heretofore mentioned, the present train control system receives its control by a continuous influence transmitted from the trackway to the vehicle, this influence being transmitted by loop circuit current flowing down one rail and back the other as one of the control influences, and by a current flowing in the two rails in multiple and back over a line wire as the other control influence. This manner of transmitting control influences should be kept in mind when considering the trackwa 1 apparatus illustrated in Fig. l.

n Fig. l have been illustrated the track rails 228 of the block J and the adjacent ends of blocks l and lli of the usual wellknown block signaling system having certain additional devices superimposed thereon, the direction of trallic being from left to right as indicated by the arrow. Each of these blocks is equipped substantially the same, and therefore like parts thereof have been designated by the same reference characters with distinctive exponents.

Each of the blocks is provided with a suitable three-position semaphore signal conventionally shown at Z, which is controlled by the track relay T of the block at the entrance to which it is located, this control being in part responsive to trailic conditions in the next block in advance by reason ot the reversal of the track circuit current by the signal in advance. The operating mechanism, hold-clear devices, and circuits for controlling the signals are omitted to simplify the description of the present invention.

Each of the signals Z is equipped with circuit controllers of well-known construction which have been illustrated in conn formity with established convention. ccoi-ding to this invention, the circuit controller is assumed to correspond to a pivoted switch arm shown horizontally by lull lines (in alignment with the blade oli the signal) which swings through 00 degrees and completes a circuit through the arc of movement indicated by heavy lines or at the points shown by dots. For example, the circuit controller 242 closes a circuit in the vertical or degree position of the signal, at the inclined or 45 degree position of the signal, and points in between; and this circuit controller also closes another pair of contacts or a circuit in the horizontal or zero degree position of the signal. It may be ex lained here, without pointing out the speci c wiring connections, that the two circuit controllers for theV signals Z are in effect pole-changing contacts.

The track relay T of the block J has its track winding under normal clear trailic conditions, as illustrated in Fig. 1, energized by track or loop circuit current su plied from the secondary winding of tg transformer 2301. The circuit for energizino' this track winding may be traced as fo lows z-beginning at the secondary winding oit the track transformer 2301, wire 2311, the usual impedance 2321, wire 2331 track rails 228 of the block J through the track' winding of the track relay T back to the other rail 228 of the block J, wire 2341 back to the secondary winding of the track transformer 2301.

The primary winding of the track transformer 2301 is energized by the secondary winding of the transformer 2351 through a circuit comprisin wire 2361, signal circuit controller 2371, wire 2391, primary winding of 'the track transformer 2301, wire 2401, the signal circuit controller 2421 of signal Z1, and wire 2431 back to the secondary of the transformer 2351. This transformer is energized from the line wires 244 connected to an alternating current generator 245.

lt should be noted that if the signal Z1 at the entrance of the block K changes from the clear to the caution position, the energizing circuit for thel track winding of the relay T will not be changed, but it the signal Z1 moves stillfurther and to the danger position the relative polarity of the track transformer 2301 is changed due to the reversal of the current flow in its primary winding by the movable contacts 2371 and 2421 operated by the signal Z1. That is, the current in the track or loop circuit for the block J will low in the normal direction when the block K in advance is a clear or caution block, but the direction of current flow will be reversed when tratlic conditions change to make the block K a danger block.

ln order to supply current in the rails flowing in the two rails in multiple, suitable high resistance shunts have been bridged between the track rails. These resistances will for convenience be called balancing resistances, because current will be ed to or conducted ed of the middle point of these resistances, thereby causing the currents to divide between the rails substantially equally. The ohmic resistance of these balancing resistances is preferably so high that their shunting effect on the track relay is negligible. ln the particular block J shown only our of these resistances are provided. The

i section of the block extending from the beginning of the block J or point A to the point B is supplied b a transformer 246. his simplex current ows through the two rails 228 in multiple for the section between points A and B through the following circuits-beginning at the secondary winding of the transformer 246, wire 247 through the balancing resistance 248, through the two rails 228 in multiple, through the balancing resistance 249, wire 250 back to the secondary transformer 246. A similar simplex circuit is provided for that portion of the block J shown beyond point B, which is supplied by the transformer 251, and comprises the secondary coil of this transformer, wire 252, contact 2531 of the track relay T1, wire 2541 or 2551, depending upon whether the block in advance is in a clear or caution condition, wire 256, through the balancing resistance 257, through the two rails 228 in multiple, through the balancing resistance 258, wire 259 back to the secondary winding of the transformer 251. It will be noted that this circuit is only broken when the block K in advance is occupied.

Uwr-caWz'eal influence receiving apparatus-0n the railway vehicle, which has been conventionally illustrated by a pair of axles and wheels, are provided suitable laminated magnetic cores for detecting, by magnetic induction, the fiow of current in the track rails as shown. These car elements comprise U-shaped cores 260, preferably made of a good quality of laminated iron terminating in enlarged pole pieces 261. These car elements are provided with coils 262. It

' should be noted that the coils on the front two elements E are wound oppositely so that the voltages induced by currents flowing in opposite directions in the two rails are cumu lative, Iwhereas the elements F on the rear of the vehicle have their coils wound alike so that voltages induced in these coils due to current flowing in the same direction in the two rails are cumulative. It is thus obvious that the front coils E will be able to detect loop circuit current, substantially all of which flows through the aXles and does not come under the elements F; whereas the elements F will detect the flow of simplex current which flows in the same direction in bot-h rails in the rear of these two axles il lustrated.

The circuit including the elements E and the circuit including the elements F lead to a suitable amplifying apparatus conventionally shown by the rectangle Q. This amplifying apparatus may take various forms, but preferably includes well-known threeelement vacuum tubes or audions which amplify the voltages induced in the circuits including these car elements. The current due to the front elements E is amplified and conducted through a winding 263of the polyin the block l under clear traffic conditions and the relay MR is energized to hold its v contact 265 in the extreme left .hand position. If the phase relation of the two currents fiowing in the windings of this relay MR is reversed, this contact 265 is moved toward the right as indicated by the dotted line 266; and if this relay is deenergized, because one or the other or both of these currents are cut off, the contact 265 will assume the pendent position as shown by the dotted line 267, due to the usual counterweigliting of the relay.

Operation of influence communicatie merma- Since the entire trackway througi train control territory is provided with both loop circuit and simplex circuit current under clear traffic conditions, the main relay MR maintains the normal energized condition as shown in Fig. l.

Let us assume now that the block K in advance of the block I is occupied. With this block K occupied by another train, the signal Z1 at the entrance to this block K assumes its danger position, thereby moving the circuit controllers 2371 and 2421 to the position corresponding to the horizontalpo-l sition of the semaphore. This causes loop circuit current to be fed into the. block J by the transformer 2301 in a reverse direction as compared with what it did when this signal Z1 was in either the clear or caution position, that is, this transformer 2301 will now be supplied by current through the following circuit eginning at the secon- Clary of the transformer 2351, wire 2361, circuit controller 2371, wire 2681, primary winding of the transformer 2301, wire 2691, circuit 'controller 2421, wire 2431 back to the secondary of the transformer 2351. In practice, the circuit controllers 237 and 242 are parts of a snap circuit controller operated by the signal mechanism, this type of circuit controller being preferred because the circuit would not remain open for an appreciable time which might affect the signals in the rear.

With the block K occupied by another train, .the track relay T1 located at the entrance of this block will be deenergized because this relay i's shunted by the axles and wheels of said another train. This deenergization of the track relay T1 causes the contact 2531 to be in the pendent position thereby leaving the simplex circuit supplied by the secondary of the transformer 251 open.

lou

The reversal of the current in the track or loop circuit of the block J causes the Contact 253 of the track relay T at the entrance to this block J to assume the reverse position (shown dotted), thereby moving the signal Z to the caution position by means and 1n a manner well-known by those skilled in the art.

As the train equipped with the apparatus just described moves through the block I with the block K occupied, the relay MR is maintained in its normal position as illustrated. As this vehicle, however, moves into the block J, this relay MR assumes the\ reverse position. This is due to the fact that the loop circuit current in the block J has been reversed, as just explained, thereby causing the current in the coil 263 to lag behind instead of lead lthe current in the 'coil 264C or vice versa, thus reversing the torque in the relay MR and causing it to assume and indicate the caution traiic conditions existing.

Let us assume now that this vehicle passes the point B in the lock J. 'As this point B is passed, the relay MR drops its contact 265 to the endent or neutral position, because there 1s no sim lex current Howing, in the rails 228 beyondtgie point B. This position of the relay MR may be assumed to be the danger position to indicate that either the simplex or the loop circuit current is entirely absent, due to a train ahead, broken rails, an 0 en drawbridge, or the like.

As the rain continues to travel from the block J into the block K (possibly at a reduced speed) the position of the main relay will not change. Although simplex current is present in the first section of the block K, no loop circuit current is present because this latter current is shunted through the axles of the train ahead, and does not reach the rear end of theblock K.

lt should be noted that any change of trafc conditions ahead will be immediately manifested on a following train, because this train is continually receiving current under clear or caution trailic conditions; and if no current is received in either or both of the windings of the main relay MR, danger traf-i fic conditions are known to exist. l

Tn addition to the various relays' used in the car-carried mechanism as shown in Fig.

` 3 there is provided suitable mechanism mechanically driven from the wheels and axles of the vehicle for manifesting when the vehicle has traveled certain distances after an adverse change in traffic conditions has taken place, the speed to which the vehicle should be restricted being dependent on the distance the vehicle has traveledl after an adverse change in traffic conditions. Also, this mechanism includes a governor or speed responsive device also driven from the wheels ofthe vehicle (not specifically illustrated) which positions a speed shaft 54 in accordance with the actual speed of the train. This mechanism also includes means for apprising the engineer when the actual speed has almost exceeded the permissive speed and when the actual speed is exceeding the permissive speed. In the particular arrangement shown (see Fig. 2) there is provided a distance cam shaft 84 about which is adapted to rotate a distance cam s'leeve 8G which sleeve and shaft are rovided `with permissive speed cams-.H only one shown) for setting up a high--to medium permissive speed and for setting up a medium to low permissive speed. These cams H, only one of which has been shown, are fastened to the sleeve 86 and shaft 84 respectively. The shape of this cam or plate H depends upon a number of factors, such as the rate of turnmg of the sleeve 86 as compared with the l speed of the train, upon whether this cam H is used for freight or passenger service, upon the braking efiiciency of the train in connec-y tion with which it is to be used, and the like; but gene-rally speaking ,is shaped so that the permissive speed of the train is reduced substantially in proportion to the reduction in the speed of the train when a brake application is made and the train is retarded in accordance with such brake a plication.

To the speed shaft 54, whicii as heretofore explained 1s turned to different positions by the speed responsive device (not shown), is fastened a speed arm 136 extending downwardly at one side of the cam H. ln the lower end of this arm 136 is fixed a pivot stud 137, and on this stud is pivotally connected the lower end of a floating lever 138. The upper end of this floating lever 138 carries a freely revolvable roller 139 which bears against the outer edge of the cam H.

lt will be observed that the lower end of the floating lever 138 assumes different positions corresponding'to the actual speed of the vehicle at that time, and that the upper end of this floating lever assumes different positions depending on the shape of the cam .H and its position. The middle point of the oating lever 138, therefore, takes a position corresponding to the combined action of speed and cam osition., The remaining parts of this mec anism include speed-distance contacts 522 and 540 which are designed to open and close when the middle point of the oating lever 138 .assumes preetermined positions.

Extending parallel to the shafts 54 and 84: and the sleeve 86 is a sector sup orting shaft 134; and mounted to turn on t isshaft are a plurality of contact operating sectors H, Hf, LP, and Lf (of which only one has been shown in Fig. 2) each counterweighted and balanced. A. connecting link 143 is pivotally connected at one end to the middle point of the Heating lever 138 and at its other endy to this contact operating sector HP, so that as the middle eine oftis coating lever shirts to the left rom the position shown in Fig. 2, this sector is rocked clockwise. torslon spring (not shown) is fastened to th1s sector HP, and shaft 34 to exert a pressure tending to move this sector counter-c ockwise, and 1 n addition to .taking up all lost motion this spring holds the roller 139 tight against the edge of the cam H.

To the sector HP, is adjustably fastened a segmental plate 146 having its outer edge formed with an arcuate portion having a depression 574 and a further depression 575. This segmental plate is adjustably fastened to the sector H, by screws 147 passing through slots in this segmental plate. By adjustment of this plate 146 the relationof actual speed to permissive speed at which suitable contacts open may be changed, that is, the depressions 574 and 575 may be shifted about the arcuate surface of the sectorHP.

Extending along the wall of the casin 1s a contact supporting bracket 150 and on t is shelf or bracket are supportedv a number of pairs of movable contact fingers. In the particular arrangement shown, both of these pairs of contact fingers are normally closed,

that is, are closed when the roller 573 rides on the main portion of the segmental plate 146. Generally speaking, these contact fingers are pivotally supported at their` lower ends and are spring pressed 1n one direction against stops, the distance between one finger and its stop being greater than that of the other finger, so that, as one finger 1s rocked back and forth the contacts on the upper ends of these fingers are separated and brought together. y

In the particular construction lllustrated, each ofv the contact fingers is formed with spaced integral ears at the lower end which ears are pivotally connected by a suitable pin or stud to the supportin standard 153. The standard 153 has a boltike extension which passes through an insulating sleeve in the bracket or shelf 150 and clamps two blocks 155 of insulating material to the bracket 150 by nuts 156, this extension and sald nuts constituting a convenient binding post for the attachment of wires. The standard 153 has an upright portion substantially parallel with its supporting contact fingers; and

fixed in the upper end of this portion is a pin or stud 157 which passes through a large hole in said linger. On the pin 157 is a compression coil spring 158 located between the `Contact finger and a washer 159 on said pin,

said washer being held in place by a small cross pin or the like. When the contact fingers are in contact with each other, as shown, the'left hand linger of each pair is a greater distance from the upright extension of the standard 153 than is the right hand finger before it strikes the standard 153 so that the contacts 522 are opened. The left hand pair of contact fingers have their clearances' so adjusted that they do not separate as the roller 573 rides into the depression 574 but are separated as the roller moves into the second depression 575. These pairs of contact fingers are operativel connected by an insulating strip 572, as s From this it is readily seen that as the train progresses along the trackway at a certain constant speed and with the sleeve 86 rotating the contacts 522 and 540 will eventually be opened. This sleeve is held in its normal position as shown under clear tratlic conditions by a cam starter magnet HCS (see Fig. 3) and if this cam starter magnet is deenergized, by reason of an adverse chan e in traffic conditions, the rotation of the s eeve 86 vis initiated, causing rotation of the cam H i-n accordanceI with the progress of the train and a gradual shifting of the sector Hp in a clockwise direction so that the contacts 522 are (pened when the roller 573 rides into the epression 574, and contacts 540 are opened into the second depression 575; this on the assumption that the speed is not reduced, as alreadly7 mentioned, and that the roller 573 actual y rides into this second depression.

On the cam sleeve cam for operating a sector Ht which c am is shaped to set up the proper permissive speed limits if the equipment is used for freight service.

In order to make the contacts governed by the freight sectors Hf and Lt ineffective while the train is operating under passenger service a suitable electro-magnet is shown directly below the shelf 150 comprising a core 208 having a winding 207 thereon, which winding if energized attracts the armature 210 in opposition to a compression spring and thereby causes the roller 528 to hold the contacts 533 and 515 (see Fig. 3) closed regardless of the position of the sector Lt controlling these contacts, the same being trueof contacts operated by the sector Hf.

In addition to the arm 136 fastened to the speed shaft 54 there are provided speed sec torsv which control contacts 441 and 486 in a manner as clearly drawings. Also, in addition to the .provi` jilon of the permissive speed sectors H and carries a distance cam H, and the shaft 84 carries distance cams L, L* and LY which (see Fig. 3)

86 is also provided a OWII.

when the roller 573 rides illustrated in Fig. 3 of the liti , are adapted to operate contactsin a man- .have been shown connected in a complete circuit diagram embodying one form of the present invention. In this diagram, the various contacts operated by the various relays are shown directly under each other and 'connected by a dotted line. Similarly, the

speed contactswhich are all operated by the same speed shaft, and the distance contacts which are operated by either the high cam sleeve or the low cam shaft, have been shown connected by a dot and dash line to show this relation between certain 'of the cams. Similarly, the high to medium speed sectors HD and Hf are shown connected to the high cam starting magnet HCS by a dot and dash line, whereas the medium to low7 sectors LP and Lt shown connected by a dot and dash line to the low cam starting magnet LCS.

ln this circuit diagram, the car-carried apparatus has been shown divided into certain groups. These groups are shown separated by horizontal dotted lines, and in this circuit diagram the several devices have been shown in their normal clear traffic condition with the vehicle running at a speed somewhere between, say, fort hour and the maximum speed t at the train is permitted to run without an automatic brake application, which for convenience is assumed to be sixty miles per hour. The various electro-responsive devices may be energized by any suitable source of energy supply available, this energy supply preferably being direct current received from a generator or some other suitable source of su ply, a battery 271 having been illustrated or this purpose. As shown, the various devices are connected between the bus wire 530 and the return Wire 547, each group of'devices being shown maintained electrically independent of the other groups as much as possible for the purpose of simplifying the Wiring dia- Generally stated, the specific arrangement shown in this divisional application contemplates, in lieu of acknowledgment of the in dications of the trackway fixed signals b a positive act, the elimination of all ca signals capable of informing the engineer as to the character of signals, whether clear, caution, or stop, under which he is running, so that the engineer must ascertain from the trackway signals themselves the existance of caution or danger traiiic conditions and can not rely upon any indications in the miles per cab. This arrangement also contemplates the provision of a Warning signal prior to every automatic application of the brakes, the imposition of a penalty for every automatic brake application, and the incorporation of means by which the engineer, by manually initiating, completing, and main taining a full service application or equivalent e'ective brake application, may forestall or prevent the operation of the auto matic brake applying devices and the resultant penalty. This arrangement further includes a scheme for giving the set up of speed limits for freight and passenger service, and in lieu of cab signals as usually' provided, provides a temporary signal indication, preferably audible, Whenever trafiic conditions become more favorable, such that the engineer, While running under a caution or stop signal, is immediately advised at any intermediate point in the block as soon as the signal in advance assumes a more favorable indication and it is safe to accelarate to higher speeds. Various other speciic features and advantages of the particular arrangement shown will be apparent from the detail description.

One significant difference between the arrangement herein disclosed and the car equipments described in the parent application is that the main car relay is used to control directly-the various other devices of the equipment, instead of controlling them through the agency of normal and reverse repeater relays. rlhis advantageous end, resulting in the elimination of two relays, is attained by rearranging the circuits and controls so as to reduce the number of contacts so that they may be operated directly by the primary or main control three-position relay MR. Accordingly, the energizing circuit for the cam starter magnets HCS and LCS, instead of being controlled by front contacts of the normal and reserve relays N and R as in Figs. 15 and 18 of the parent application are controlled b J normal and reverse contacts on the main control relay itself, namely, the high cam starter magnet HCS is energized by a circuit through the normal contact 500 of the main control relay, as will be obvious from the drawing, and the low cam starter magnet LCS is energized through normal or reverse contacts 501 or 502, respectively, of said main control relay.

llt will, of course, be recognized that a train must receive energy from the trackway in order to proceed at a speed greater than the minimum speed, assumed to be about 15 miles per hour. In the practical application of this system to railroads, it is obvious that all portions of the trackway used by a locomotive or train can not, as a practical proposition be supplied with the train cont-rol or signaling current. For example, there will be lll) - sidings, yard limits, roundhouses, and similar places on a railroad' Where it Would be impractical to sup ly thesimplex and loop circuit currents. Xlso, it would not be advisable to equip all portions of a railroad or engine division at one time and put the system into service simultaneously over this Whole road or engine division. Again, locomotives or trains may `be obliged to travel occasionally, particularly in emergencies, overforeign roads. Other conditions may arise in practice Where itis desirable toallow the train to travel faster than 15 miles per hour over territory not equipped with signaling current and its control. Consequently, this invention contemplates theprovision of means for cutting out the system, or renderingit inei'ective to enforce its minimum speed-restrictlon, even though the car relay is Wholly deenergized because of the failure to p ick up simplex or loop circuit current. .Ob-

fv1ously, such cutout or eliminating means, While desirable for unsignalled or unequipped territory, must be safe-guarded in such a Way that the engineer can not carelessly or maliciously4 defeat the objects of the invention and renderthe system in'efective in regular service in equipped territory.

This desirable control for unsignalled territory is obtained by providing' a special I relay NS, togetherv with suitable manual and automatic control therefor, such that the desired end may be obtained for unslgf nalled or unequipped territory, vbut the safe-` fitvryvice and circuits is shown 1n F1g. 3 1n thev ty of the system ,retainedfor equipped ter- This relay NS and its control de control relay and indication group.

Referring to Fig. 3, the NS relay may be energized by a circuit beginning at the bus Wire 530 and including contact 503 of the relay MR, front contact 426 of the push but.

ton relay PBR, upper `Winding of the relay NS, and Wires leading to the other bus 547.

It. Will be noted that this circuit includes the contact 503 of the main relay MR, and consequently, the relay NS can not be energized under caution or danger conditions. ln other Words, after speed control is in `force in a caution or danger block, the relay NS cannot be energized.

Instead of cab signals or indicatorsof the usual construction, the arrangement of Fig. 3 provides a cab indicator 505, preferably a lamp of suitable color, such ask green, `Which is energized so long as the NS relay is deenergized, that is, so longpas the train is running inregular block signal territory and under the control of the automatic system. The energizing circuit for the lamp 505 through the `back contact of the NS relay Will be evident in Fig. 3. It should be noticed that this lamp is not extinguished whenthe train enters a caution or danger block; and consequently, the indication of matic train control protection, lthere isA also provided in ,Fig."3 another indicator, such as a White lamp W, which is included in \a circuit directly from one bus 330 to the other bus 547 and including the stick contact 296 of the NS relay and the contact 504 of the relay MR, and'is lighted while the train is running in unsignalled territory. ,'jThus, while the train is traveling in signalled territory there is a persistent indication, such as a` greenlamp; and While the vtrain 'isf running in unsignalled territory, this green indication is extinguishedfand another indication, vsuch as a White lamp, is given persistently, with the result that the engineer is constantly advised Whether his train is running with or without the protection afforded by the automatic train control system.

For various reasons hereinbefore indicated it is considered to be preferable, under certain circumstances at least, to require the engineer to kee alert and Watch out for the indication of t e usual trackway block signals, Where such signals are used. In other Words, the engineer derives the information as to the existence of cautionary or danger traiiic conditions from the regular block signals on the trackwa'y, rather than from indications irl-the cab, with the result that a sort of dual protection is afforded and the safety of the train is not dependent solely upon the proper performance of that part of the train control system by which iniiuences or controls corresponding to traffic conditions are communicated from the track to the train. Putting it another Way, the protection to train movement afforded bythe regular block signal system and the -cngineers observance of the indications of the block signals is largely retained, if not Wholly, and the train control system is held in reserve. for those extremely rare occasions Where there is a failure of the block signal system or the vigilance of the engineer.

In conformity with this theory, the arrangement shown eliminates all ,indicators in the cab which show the existence of caution or danger conditions. It is, however, highly desirable to immediately advise the engineer of a favorable change in traflic conditions, that is, from caution to clear, or from danger to caution or clear, in order that the engineer can resume speed Without delay, and even though, on account of curves or other conditions, he can not determine the indication of the signal ahead. For the purpose of giving such desirable information upon a favorable change in traffic conditions, without giving corresponding information as to unfavorable changes, there are rovided in the modification of Fig. 3 two indicators, preferably audible, which are so arranged and controlled as to be operated temporarily only if there is a change from danger to caution or from caution to clear, but which are not operated if the traffic changes are from clear to caution or caution to danger. Specifically, these indicators are single stroke bells or gongs 507 and 508 of the usual or suitable construction and are energized, respectively, by the closing of contacts 509 and 510 upon return of the high cam H (shown in Fig. 2) and the low cam (not shown) to the normal initial position. These contacts 509 and 510 are governed by distance cams H and L, respectively, associated with the high cam sleeve 86 and the low cam shaft 84 respectively.

When the train is traveling under a clear signal, the contacts 509 and 510 are closed and the bells 507 and 508 are energized; but since these bells are of the single stroke type, their armatures or cores remain attracted without giving an sound. When the train enters a caution b ook and the high cam is started, contacts 509 open, without sounding the bell 507. As the train proceeds and the low -cam is started, the other bell is likewise deenergized without producing a sound. lf, now, while the train is running in a caution block with the high cam operating, the block ahead should become unoccupied and the signal at the entrance thereto assume a caution or a clear position, the main car relay at once responds for reasons hereinbefore explained, energizes the high cam starter magnet HCS and causes closure of the contacts 509 as the high cam shaft returns to the normal or initial position. rlhe closure of the contacts gives a single stroke of the bell 507, thereby advising the engineer of the existence of more favorable trafii'c conditions. Similarly, if the train is traveling in a danger block with thelow cain operating and this danger block changes to caution, restoring the low cam to the initial position, there is a sounding of the other bell 508. Similarly, if the train is traveling'in a caution block in advance of the point B therein, and

this block changes to a clear block, both of the bells are sounded. The bells will have a distinctive tone, or will in some other way be madereadily distinguishable, it being understood in this connection that a whistle or other audible device and even visual indicators may be used instead of the bells described, rovided that such indicating dev ices shallhave the analogous characteristic of being operated only upon closure of the energizing circuit therefor.

The warning or audible signal 512, as shown in Fig. 3, is controlled on the closed circuit principle and is eiective at all points in the cam run out, that is, on the curved or sloping ortions of the cam curve as well as on the liorizontal portions, it beiner obvious that expedients similar to that s own in Fig. 15 of the parent application may be incorporated if desired, to make this warning signal eflective only upon the horizontal portions of the cam curve. The regular energizing circuit for the magnet of the warning signal, as readily seen in Fig. 3 Iincludes contacts for freight and passenger trains operated jointly by the low cam and governor, and freight and passenger contacts operated by the high cam and governor, respectively, connected in series. This circuit comprises wires 513 and 514, contact 515, wire 516, contact 517, wires 518 and 519, contact` 520, wire 521, contact 522, wire 523, warning signal 512 and wire 524. The contacts, both for freight and passenger, of the low cam are shunted by a partial circuit including wires 525 and 527 and contact 526 governed by the distance cam I? on the low cam shaft, this contact being closed with'the low cani shaft in the initial and normal position and being opened as quickly as mechanical expedients will permit after the low cam is started.

rlhe particular cam-governor contacts for freight and passenger service are alternately or selectively rendered effective by mechanically controllng the movement of the freight or lower speed contacts in the manner shown in Fig. 2. Referring to Fig. 2,

`a magnet and armature construction similar to that shown in Fig. 12 of the parent application, is arranged to hold the contacts closed irrespectivewof the sector, this being accomplished by a roller 528 on an arm attached to the armature of this magnet and arranged to bear against the outer linger of the two pairs of contacts. Consequently, when this magnet lis energized, the contacts for the freight service are maintained closed independently of the operation of the low cam and governor. rlhis magnet for changing from passenger to freight service is energized b the closing of a locked or sealed Switch OS (see Fig. 3) through the following circuit z-beginning at the battery 271, wires 530 and 600, switch COS, wire 601, magnet 2071, wire 602, magnet 207 H, wires 603 and 547, back to the battery 271.

The electro-pneumatic valve or brake control device E. P. V.. has a stick or maintaining circuit which may be traced as follows zcommencing at the positive bus 530, wires 531 and 532, through freight and passenger low cam-governor contacts 533 and 535 connected by Wi re 534 (shunted by a Contact 548 on the low distance cam Ly opened as soon as the low cam starts), wires 536 and 537, freight and passenger high cam-governor contacts 538 and 540 connected by wire 539, wires 541, 542 and 543, front contact 340 of the E. P. V., wires 544 and 545, winding of the E. P. V. wire 546to the other bus wire 547.

The electro-pneumatic valve E. P. V. may also be maintained energized through its stick contact, independently of the opening of these cam-governor contacts, provided 1) the engineers brake valve is in the servlce position, or (2) there is a predetermined application of the brakes actually in effect or will necessarily come into effect in due course. Consequently, if at any time before the train exceeds the critical speed limits prescribed by the cam and governor contacts, the engineer initiates a manual brake application by placing his brake valve in the service posltion, or has done all that is necessary to make an eective brake application, then the electro-pneumatic valve is maintained energized independently of the opening of the cam-governor contacts. For this purpose, there is provided upon a regular engineers brake valve, a pair of contacts closed only if the valve is in the service, or if desired, also the emergency position. As indicated in the diagrammatic showing, an insulated sector 553 is fixed tothe valve stem of the engineers brake valve, and on this sector is a contact piece 554 arranged to bridge a pair of insulated contact springs or fingers 555 if the brake valve is in the service position. With these contacts closed, the electro-pneumatic valve may be energized by a circuit traced as follows beginning at the positive bus 530, wires 556 and 557, contacts 555, Wires 558, 559 and 543, front contact 340 of the E. P. V., wires 544 and 545, winding of the E. P. V., wire 545 to the negative bus Wire 547.

lt will be evident to those skilled in the art of air brake systems that it is unnecessary and undesirable to leave the engineers brake valve in the service position after the desired reduction in equalizing reservoir pressure has been obtained. To explain, the brakes are manually applied in the usual type of automatic air brake system by moving the engineers valve to the service position, thus reducing the pressure in the equalizing reservoir, this reservoir in turn with the agency of the so-called equalizing piston valvereducing the pressure in the brake pipe to a forresponding extent. Roughly speaking, the equalizing reservoir pressure may be reduced enough to give a full service application, that is, a reduction equal to equalization, accomplished by leaving the engineers brake valve in" the service position some six or seven seconds. Since nothing is gained by spring 562 is reducing brake pipe pressure below the point of equalization, it is likely unnecessary to reduce the equalizing reservoir pressure below that point, and consequently, after the engineers brake valve has been left in the. service position long enough to reduce 'the equalizing reservoir pressure to the extent desired for effective braking, it is permissible so far as the braking effort is concerned, and desirable from the standpoint of avoiding unnecessary venting of brake pipe pressure, for the engineer to move his valve out of the service position into the lap position. For these reasons, in multiple with the contacts on the engineers brake valve, there are provided in the arrangement shown in Fig. 3 a pair of normally open contacts which are automatically closed only if the equalizing reservoir pressure has been reduced-to a predetermined extent corresponding to the amount of brake application desired.

Referring to Fig. 3, the simplified and diagrammatic arrangement shown comprises a cylinder 560 provided with a piston 561 of the usual type held in a normal position by a spring 562. The chamber on the spring side of the piston 561 is connected to the equalizing reservoir of the braking system by al pipe 563, and the chamber on the other side of the piston is connected by a pipe 564 to a source of suitable standard pressure corresponding to the initial brake pipe pressure. Since the brake pipe pressure ordinarily is equal to feed valvepressure (the brake pipe being connected to the feed valve when the engineers brake valve is in the normal running position), it is considered expedient to connect the pipe 564 directly to the feed valve. In certain systems, however, the feed side of the feed valve is at times connected to main reservoir pressure; and in systems of this kind, or when desired, this pipe 564 may be connected to a separate feed valve providing the desired standard pressure. The properly tensioned so that the contacts 565 are bridged by the contact disc 566 when a predetermined reduction of the pressure in the equalizing reservoir has been made, corresponding to the amount of reduction which the automatic devices are designed to give. The contacts 565 are connected in multiple with the contacts 555, so that the engineers brake valve may be returned to the lap position as soon as the equalizing reservoir pressure has been reduced to the proper value without causing an interruption of the circuit heretofore traced which energizes the E. P. V. independently of the cam-governor contact.

By virtue of the organization for the control of the electro-pneumatic valve E. P. V., as just described, it is possible for the engineer to forestall and prevent deenergization of said electroneumatic valve providing he is initiating a rake application or, so far as his control of the air brakes are concerned, he has consummated an application. It may be ex lained here that, since the automatic bra e application for the train will probably, in the interests of shortening the block lengths and facilitating train movement, be based upon a substantially full service application, the manual brake application which the engineer must initiate or consummate in order to forestall such automatic brake application, should like- Wise be a substantial y full service application; and the present discussion is based upon this assumption.

To make clear the utility and advantages of this forestalling arrangement, assume that the train enters a caution block,V the high cam being started in the manner already explained, and a curve of limiting or permissive speed being prescribed. Now, this speed-distance or cam curve will have its shapeor location with respect to the next signal or stopping point so selected that, if the automatic brake applying means acts at the point and speed indicated by this curve, the resulting automatic brake application at that instant initiated will come .into effect and retard the train quickly enough to bring it to a stop, or to a safe low speed, before the signal ahead or sto ping point is reached. ln other Words, t e cam curve is predicated on the' assumption that a 'full service brake application initiated at the time the train crosses this curve will bring the train to a stop safely. Consequently, a manual brake application of the saine magnitude initiated at the saine oint would accomplish the same end. The interests of safety, therefore, are satisfied if, at the instant the cam-governor contacts open, the engineer has his brake valve in the service position and keeps it there so long as said cam-governor contacts remain open and until the equalizing reservoir pressure has been reduced enough to assure a full service application.

The system shown in Fig. 3, therefore, considerably smplifies the problem of providing a speed restricting apparatus which requires the engineer to do what is necessary to stop a train under certain traiiic conditions before reaching a signal at stop, or a danger zone, and which penalizes the engineer if he does not properly control the train under these conditions. lor instance, the cams heretofore described may be cut in a manner so that the permissive speed set up will be ideal for average conditions, that is, will just bring the train to a stopI or a predetermined low speed before reaching a danger zone if the brakes are initiated at t-he permissive speed at` any point on a level grade. Considering novv down-grade territory with this same apparatus, the trackvvay simplen and loop circuits Will in this event namens be so laid out that the cam is initiated early enough, so that, with the permissive speed ideal for level track set up, this permissive speed may be exceeded and the train may still be brought to a stop automatically before reaching the end of the block (presuming the engineer did not initiate a manual brake application). I

Since the cam mentioned is out for level Grade, it is impossible for the engineer to keep the speed below the permissive speed setu by this cam on down grade, even thong he ap lies the brakes -in the usual manner. Un er this condition, however, he

Will not be penalized because the contacts 555 or 565, as the case may be, are closed and prevent the E. P. V. from being deenergized, and the penalty heretofore mentioned, inicted. The problem of penalizing the engineer if he oes not properly control the tran is, therefore, much simplified, because a single cam may be employed for u and down grades as well as level track Without inflicting a penalty upon the engineer if he crosses the cam curve or permissive speed line with the brakes applied or a predetermined brake application initiated.

ln addition to gradually restricting the permissive speed on entering caution territory by the cani governor mechanism as just described, entrance into caution territory also causes deenergization of the single stroke bell 507 a short distance of travel after the main relay MR lchanges from normalto reverse, this because the redetermined rotation of the high cam sha t rotates the cam Hu and opens contact 509 after a short distance of travel. This deenergization of the bell 507 does, however, not produce a sound so that the engineer is not informed of this unfavorable change in traffic conditions by cab signals, but he must look to Wayside signals for such information for reasons already given. Also, when the actual tra-in speed is almost as high as the permissive speed the audible signal 512 is deenergized, thus informing the engineer that he Will be penalized if he does not take appropriate action. This penalty consists in requiring the train to be brought substantially to a stop, and results by reason of the engineers failure to reduce the speed of the train by cutting off power or by his failure to apply the brakes and in so doing avoid de-energ'ization of the device E. P. V., because if the brakes are applied and held applied while the device E. lP. V. is still energized this device E. P. V. is maintained energized through one of the pairs of contacts 555 or 565, or both pairs of contacts. After the penalty has been inflicted, that is, the train speed has been reduced to less than two miles per hour, contact 486 closes the following circuit for rei-energizing the device EL P. V.:-beginning at the positive llo ` tion into danger territory causes the relay MR to assume its deenergized position thereby deenergizing the low cam starter magnet LCS and initiating the low cam shaft 84. After a certain distance of travel in danger territory contacts 510 are opened thereby deenergizing the single stroke bell 508, contacts 526 are opened thereby removing the shunt around the low speed audible contacts 515 and 517, and opening of contacts 548 removes the shunt around the permissive speed contacts 533 and 535, so that the low to medium speed audible and brake control contacts are now effective. The delayed response of the contacts 526 and 548, the opening of which is delayed by distance of movement, is resorted to in order that the movement of a train over dead sections, such as encountered at frogs and the like, does not make these audible and brake control contacts 515-517 and 533-535 effective.

Having now explained how the automatic train control apparatus operates torestrict the speed of the train upon entering caution and danger territory this automatic restriction being preventable by the engineer if he applies the brakes in a manner as already explained, let us now consider what changes take place Whenthe train re-enters more favorable territory. Let us first assume that the train passes from danger into` caution territory; this change in traflic con ditions causes the main relay MR to change from its deenergized position to its reverse energiag-d position thereby reenergizing the low cam starter magnet LCS which causes restoration of lov7 cam shaft to its normal position. As the low cam shaft upon its return to normal reaches its normal position the circuit for the single stroke bell 508 is completed thereby giving amomentary audible sound informing the engineer that he may release the brakes and again increase the speed of the train. Also, the return of the low cam shaft 84 to normal recloses contacts 526 and 548 thereby making the low speed audible and brake control contacts heretofore mentioned ineffective.

Let us now assume that the train passes from caution to clear territory, thereby causing the main relay MR to change from its reverse to its normal energized position. This causes energy to be reapplied to the high cam starter magnet HCS thereby restoring the high cam sleeve 86 to normal, giving a single tap on the bell 507 and reestablishing the maximum clear trafiie speed limit. In connection With the cam and governor brake control contacts 540, and 535 and the audible. signal'contacts 522 and 517 it should be noted that the circuits controlled by these contacts are normally energized circuits and that opening of these circuits produces a brake application or an audible signal by the normally energized brake control device E. P. V. or the audible signal 512 as the case may be, and that, for reasons heretofore given, the audible signal Contact 522 or 517, as the case may be, is opened as the roller 573 rides into the depressions 574 and that the brake control contacts 540 or 535 as the case may be are opened as the roller rides into the second or lowest depression 575.

Let us now consider how this apparatus may be used on a train in freight service. If the train is to be used for freight service, an authorized person will unlock the box and open the switch COS. This causes the magnets 207 to be deenergized thereby allowing the contacts controlled by the freight sectors Hf and Lt to assume positions depending on the position of these cams, and since the permissive speed limits for freight are always lower than for passenger, the contacts controlled by these freight cams will restrict the train to speed limits considered proper for freight train service under existing trafiic conditions ahead.

Entering unsg-nalled terrz't0rg/.At the point where the train enters the unsignalled or unequipped territory, it is assumed that the main car relay MR will be energized with a normal clear polarity; this result may be assured by providing a track section, permanently supplied With loop and simplex circuit currents of normal polarity, at the entrance to each portion of unsignalled territory. Such a permanently clear section, among other things, might obviate the necessity of the train waiting in the last block of signalled territory until this block became clear. In this connection it should be remembered that the relay NS cannot be picked up unless the relay MR assumes the normal clear condition, and cannot be thereafter held up through its stickcircuit unless the relay MR assumes its danger condition. In other words, a change from clear to danger is required to set up the unsignalled territory condition on the train, and for this llll reason it may by some signal engineers be energized at the time.- The engineer is eX- pected to operate the ush button PB, and in so doing picks up tie push button relay PBR and energizes the upper Winding ot' the relays NS by the circuit heretofore traced. As the train then enters the unequipped or unsignalled territory, and the main car relay MR' is deprived of energizing current, it assumes its deencrgized position closing its contacts 504, thereby establishing a stick or retaining circuit for the lower winding of the relay NS said circuit including the contacts 504C and 296. I

lt will be observed that the energizing circuit for the upper winding of the relay NS is broken at the normal Contact 503, While the stick circuit for the lower winding is being completed at the deenergized contact 504 of the main relay MR, and the relay NS is preferably made slightly slow acting in dropping to span this slight time interval, as conventionally shown, or by well known expediente, said contacts 502-3 and 504 are made slightly overlapping in their operation.

The relay NS, when energized, renders the system inactive and performs functions as ollows:-

(a) rlhe opening of its back contact 296, interrupts the circuit :tor the green lamp 503, so that, although the main relay MR is deenergized in the unsignalled territory, the red lamp is not lighted. Thus, there are no cab signals or indicators appearing While the train is traveling in unsignalled territory, thereby avoiding all chance of confusing or misleading the engineer.

(b) With the relay NS energized, there is established a circuit for lighting the lamp W, this circuit being the same as the stick circuit NS previously traced except that the lamp W is substituted for the lower winding of the relay 415.

rlhe lamp W represents a suitable indicator or cab signal giving a special or distinctive indication, in this instance assumed to be a white lamp. This special rio-signal indication is constantly displayed before the engineer while his train is traveling in unsignalled territory and serves to remind him that the train is running without the protection of the automatic speed control system, the responsibility for the safety of the train being Wholly in his hands and requiring care and a speed permitting stoppage within vision.

(c) The relay NS, when energized, closes front contacts 437 and 438, which, as will be readily seen from the circuits in Fig. 3, shunt the contacts 500 and 50i-502 respectively, and maintain the high cam starter magnet HCS and the low cam starter magnet LCS energized, irrespective of the pos?- tion of the main relay MR. ln short, the relay NS maintains the cams in their normal or initial speed conditions,iin spite of nii-' One peculiarity of the circuit arrangement i of Fig. 3 meriting consideration is that the relay NS is energized each time the push button PB is operated, While a train is traveling under a clear signal. This condition, however, is merely temporary or transient. Even though the relay NS is energized, the picking up of the push button relay PBR which is necessary to energize NS opens at its back contact 316 the circuits for the high and loW cam starter magnets HCS and LCS thereby bringing about the enforcement of a restricted speed limit. Hence, the engineer derives no advantage b holding down the push button PB with t e idea of keeping the relay NS energized. ln this connection, it should be noted that the relay NS can only be picked up by the push button PB when the relay is in the normal position.

As a result of the control of the relay NS just described, this relay can not be energized and maintained energized except when there is a change from clear control to danger control. Such a change from clear to danger does not occur in the regular operation, each danger change being anticipated by a change from clear to caution, the only exception being where there is a broken rail in the same block, or an open switch, or the like. Consequently, the no-signal territory condition can only be set up where unsignalled territory actually exists, that is, in running from clear to danger, because even in those Cases where a broken rail or the like in the same block produces a sudden change from clear to danger, the relay NS will not be energized inasmuch as the engineer, not knowing that such condition will occur, will not have operated his push button PB.

Reenterz'ng .signalled territory.

supplied, the relay NS is automatically deenergized and the proper speed control for the train is automatically put into effect.

When the relay NS is deenergized, the white lamp W is extinguished, and the lamp 505 is lighted; the cam starter magnets HCS and LCS are put back under the control of the main car relay MR.

Emergency control for unsignalled territory.`

The setting up of the control for unsignalled territory requires, as above eX lained, a manual operation on the part of t e engineer at the right time. It may happen, however, that the engineer will not make timely operation of the push button PB and his train may get into unsignalled territory without having the relay NS energized. lVhile the train may, of course, even then proceed at ysome speed lower than the minimum of 15 miles per. hour, the stretch of unsignalled territory may be long `and a higher speed desirable. Considerable delay and danger to following trains might result if the engineer attempted to back up into signalled territory and try to carry out the proper procedure in entering the unsignalled territory. v

Also, there may be occasional power failures, where several blocks of the railroad will be dead, due to trouble with the transmission line or similar accidents. Such power failure, could not, of course, be anticipated by the engineer and enable him to pick up the relay NS, with the net result that without using some other special emergency cut out, the train or trains affected by this power failure could not proceed faster than the minimum speed limit of 15 miles per hour.

To take care of these contingencies, a special push button 440 for energizing the relay NS is provided, together with contacts 441 closed only if the speed of the train is below 2 miles per hour or substantially at a stand still. This emergency', push button 440 is in practice located in a sealed or locked box, equipped with a recorder or otherwise safeguarded so that its use can not be abused. lf the engineer should fail to take the appropriate action in entering unsignalled territory, or there should be an unexpected power failure, the train may be brought to a stop and the push button 440 operated to pick up the relay NS through a circuit including the push button Contact 440, the contact 441 only closed if` this speed of the train is less than 2 miles per hour, and the upper winding of the relay NS.

Since the main relay MR under the conditions assumed is deenerglzed, a stick circuit for the relay NS heretofore considered is at once established; and the train may proceed under the regular unsignalled territory control.

The audible signals 507 and 508 are preferably so constructed that no sound of any erably accomplished by constructing these stop posts of suitable resilient material,A such` as rubber, cork, or the like.

In this system, the penaltyv consists of requiring the train to be brought to avery low speed (say, two miles per hour) and requiring the engineer to push the acknowledging push button PB, thereby closing the contact 57 6 of the push button relay PBR shunting the front contact 340 of the E. P. V., and closing the pick-up circuit for the E. P. V. heretofore traced.

Having thus shown and described a specific system embodying the present invention, it is desired to be understood that certain specific disclosures have been made for the purpose of illustrating the nature of the invention, rather than the scope thereof, and that the invention is not limited to the specific structure illustrated. Also, the invention does not alone reside in the particular systems disclosed, but also resides in certain sub-combinations and elements; and it is to beunderstood that various changes and modifications may be made to adapt the invention to the various types of railway systems in connection with which it is to be used.

What is desired to be secured by Letters y Patent of the United States, is:

1. Car-carried apparatus for automatic train control systems comprising, a speed responsive device which at all times assumes a condition dependent upon the actual speed of the train, a permissive speed cam adapted lto be driven by the wheels of the train for 'train service, a circuit which if closed prevents the permissive speed cam for freight train service from being effective, manually operable means for closing said circuit, and means for protecting said manually operable means against being operated by unauthorized persons, whereby failure of said circuit creates a condition on the side of safety and sets up speed limits suitable for freight train service.

2./ Car-carried apparatus for automatic train control systems comprising, an electropneumatic brake applying means on a railway vehicle for controlling the usual air brakes, a circuit for normally energizing said brake applying means; and means for controlling said circuit including two independent devices in series, one of said devices comprising a permissive speed device for -setting up various speed limits between a medium speed and a maximum speed which will interrupt said circuit if the actual speed exceeds the permissive speed and the other device comprising, e a similar permissive speed device for settin up various permissive speeds between sai medium s eed limit and a predetermined lo1I speed imit, and which will interrupt said circuit at another point if the actual speed exceeds the permissive speed, and means for at times rendering the latter device ineffective.

3. In an automatic train control system of the continuous inductive type in which the train is permitted to proceed in response to the flow of current fiowing in the track rail directly ahead of the train, the combination with a normally energized electrically operable device adapted to cause an automatic application of the brakes of the train when de-energized, an air brake system including the usual equalizing reservoir, and means for independently maintaining said device energized including an auxiliary circuit for said device having contacts therein, said contacts being operated by a fluid pressure device connected directly to the equaliz- `ing reservoir and edective to close said contacts When the pressure in the equalizing reservoir has been reduced toa predetermined extent belovv its normal value.

4. Car-carried apparatus for automatic train control systems comprising, a normally energized electrically operated brake control device connected to the usual air brake system in a manner to eilect the application of the brakes when de-energized, a main circuit for energizing said device including a front contact of said device closed only when said device is in its energized condition, another circuit for energizing said device also including the front contact of said device, fluid pressure circuit closing means connected directly to the usual equalizing reservoir of said air brake systems and constructed to cidse its contacts when the equalizing reservoir pressure has been reduced to a predetermined extent, contacts associated With the engineers brake valve of said air brake system closed when said brake valve is in a brake applying position, said another circuit including in multiple the contacts of said iuid pressure circuit closing means and the contacts associated with said engineers brake valve, whereby said brake control means is not de-energized even though its main circuit has been opened by suitable train control means providing the engineer is applying or has a plied the brakes.

5. gar-carried apparatus for automatic train control systems of the type in which a suitable electro-responsive device on the car is continuously maintained energized inductively by influences transmitted from suitmore favorable change .of traic conditions ahead. V

6. Car-carried apparatus for automatic train control systems of the type in which a suitable electro-responsive device on the car is continuously maintained energized inductively by iniuencestransmitted from suit- \able trackvvay apparatus under predetermined favorable traii'ic conditions ahead including, a control relay, speed restricting apparatus governed by said relay, and signalin means only effective momentarily for in icating a change in the speed restricting condition of said apparatus. n

7. Car-carried apparatus for automatic train control systems of the t e in which a suitable electro-responsive device on the car is continuously maintained energized inductively b influences transmitted from suitable trac Way ap aratus under predetermined favorable tra c conditions ahead including, a control rela a permissive speed device, an actual spee device, a brake controlling device for applying the brakes of the vehicle if the actual speed exceeds the permissive speed, and signaling means for momentaril indicating when said permissive speed evice changes to a less restricted speed condition.

8. Car-carried apparatus for automatic train control systems of the type in which` a suitable electro-responsive device on the car is continuously maintained energized inductively by influences transmitted from suitable trackway apparatus under redetermined favorable traffic conditions ead including, a control relay, speed restricting apparatus governed by said relay, and means for sounding an Ialarm only when said speed restricting apparatus changes to a higher speed restricting condition.

9. An automatic train control system comprising, a control means governed by induences transmitted from the trackway in accordance With traffic conditions ahead, train govering means controlled by said control means, and an audible signal having its control Winding ener ized under iavorable trac conditions an de-energized under unfavorable trac conditions, said audible signal being so constructed that it produces a sound only When it is changing from its deenergized to its energized condition and not 'when changing from its energized to its deenergiaed condition.

10. An automatic train control system comprising, a normally energized electroresponsive brake control device which if deenergized applies the brakes of the usual llll) air brake system, contacts for govering said device when used 1n freight servlce and contacts for govcning said device when used in passenger service connected in series, automatic means for independently governing said contacts, and separate means for closing said freight governing contacts independently of'said automatic means.

11. Car-carried apparatus for automatic train control systems of the type in which a suitable electro-responsive device on the car is continuously maintained energized only so long as influences are transmitted to it from suitable trackway apparatus under predetermined favorable trallic conditions ahead including, a control relay, means for energizing said relay in response to current flowing in the track rails said means including an amplifying device, a normallvener- ,'gized brake control device acting on the usual air brake system governed by said relay, means for .de-energizing said brake control device under predetermined traiiic conditions ahead, and means for independently maintaining said brake control device energized effective only if the engineer manually initiated or is mainta'ning a brake application of a predetermined degree.

12. Car-carried apparatus for automatic train control systems of the type in which a suitable electro-responsive device on the car is continuously maintained energized inductively by iniuences transmitted from suitable trackway apparatus under predetermined favorable traffic conditions ahead including, a control relay, a permissive .speed device governed by said control relay, an/

actual speed device, a control device acting on the usual air brake system for applying the brakes if the actual speed exceeds the permissive speed, means for inflicting a penalty upon the engineer if said brake control device is actuated, and means for preventing said brake control device from being actuated only if the engineer takes such action as will actually reduce the speed of the train as quickly as the automatic'brake control device is capable of doing.

13. Car-carried apparatus for automatic train control systems of the type in which a suitable electro-responsive device on the car is continuously maintained energized inductively by influences transmitted from suitable trackway apparatus under predetermined favorable traflic conditions ahead including, a control relav, a permissive speed device governed by said control relay, an actual speed device, a control device acting on the usual air brake system which applies the brakes if the actual speed of the vehicle exceeds the permissive speed, means for inflicting a penalty upon the engineer if said brake control device is actuated, and means for preventing said brake control device y from being actuated if the usual engineers brake valve is inthe service brake applying position or an adequate brake application has been initiated by the engineer.

14. An automatic train control system comprising, a pair of contacts biased to a circuit opening position, means governed in accordance with the actual speed of the vehicle as compared with a variable permissive s eed for holding said contacts to circuit c osing position, a brake control device governed by a circuit including said contacts, and a fluid pressure operated switch connected directly to the equalizing reservoir \including contacts closed when a. predetermined reduction in equalizing reservoir pressure has been made for shunting said irst mentioned pair of contacts.

15. In an automatic train control system, Ithe combination with a railway vehicle having a braking system includingy the usual lengineers brake valve and an equalizing reservoir normally charged to brake pipe pressure and of automatic means for applying the brakes of the vehicle under predetermined conditions ofthe braking system, the speed of the vehicle and traiii'c conditions ahead comprising, an electro-pneumatic valve normally energized by a stick circuit including a front contact controlled by said valve, a normally closed contact in said circuit for controlling said valve automatically if the speed of the vehicle exceeds a predetermined speed limit, means for independently maintaining said stick circuit vclosed effective only when the pressure in the equalizing reservoir has been reduced from normal brake pipe pressure to a predetermined extent, andmanually operable means for shunting the front contacts of said valve effective only -if the speed of the vehicle is below a predetermined low value, whereby if the electro-pneumatic valve is operated the engineer is penalized by being required to bring the train to a predetermined low speed before the electro-pneumatic valve can again be re-energized.

16. In an automatic train control system, the combination with a railway vehicle equipped with the usual air braking apparatus including the usual engineers brake valve and an equalizing reservoir normally charged to brake pipe pressure; of means for actuating said apparatus to apply the brakes comprising, an electro-responsive device energized by inliuences transmitted in response to currents flowing in trackway circuits which are only present under favorable t-raiic conditions ahead and eective to instantaneously respond to a change in such traffic condition, brake applying means rendered effective upon de-energization of said electro-responsive device for automatically applying the brakes whenever the vehicle exceeds a predetermined speed limit at any time while said` electro-responsive device is cle-energized, and means for preventing said brake applying means from being actuated effective only if the engincers valve is in the service brake applying position or a predetermined reduction in pressure if the equalizing reservoir has been made, whereby if the engineer has applied the brakes to slow down the train under danger traffic conditions he may release them as soon as traffic conditions become more favorable regardless of the position of the train in the block.

17. In an automatic train control system, the combination with a railway vehicle provided with that type of braking system in which the brake pi e is normally supplied with pressure whicii if released will cause an automatic application of the brakes and including, a brake valve and an equalizing reservoir; and of apparatus for automatically appl ing the brakes under predetermined con itions of the braking system, the s eed of the vehicle and traffic conditions a lead comprising, an electro-responsive device maintained energized by suitable trackway apparatus which responds to traffic conditions ahead, whereby the electroresponsive device responds to changes of traffic conditions ahead, a normally energized brake applying device effective to applly the brakes if de-energized, means for brea ring the circuit of' said bra-ke applying device if and so long as the vehicle exceeds predetermined speed limits determined by the condition of said electro-responsive device, means operable upon a predetermined reduction in the pressure in said equalizing reservoir for independently maintaining said brake applying device energized provided it is already in its energized condition, and penalizing means causing brake applying device to be maintained de-energized irrespective of said last two mentioned means effective when the brake applying means has assumed its effective position.

18. In a train control system for railway vehicles equipped with automatic air brake systems in which the brakes are applied by reducing pressure in an equalizing reservoir, the combination withV said equalizing reservoir, an engineers brake valve of the usual construction for controlling the pressure in said reservoir, and contacts associated with said brake valve closed when said brake valve is in a brake applying position, of a biased circuit controller having contacts in multiple with said first mentioned contacts1 and means for automatically operating said circuit controller as soon as the equalizing reservoir pressure has been reduced to' a predetermined extent with respect to the normal running brake pipe pressure consisting of a piston urged in a direction to, open the contacts of said circuit controller by a spring and equalizing reservoir pressure and urged in the opposite direction by feed valve pressure, whereby the circuit controlled by these contacts is closed only if a Abrake application is'being or has been made.

19. An automatic train control system comprising, brake control apparatus controlled from the trackway and adapted while active to establish a predetermined continually restricted speed limit, said apparatus including a normally energized electro-responsive device and means tending to cause de-energization of said device whenever the vehicle exceeds said speed limits, a circuit for maintaining said electro-responsive device energized independently of its control by said apparatus as the result of excessive speed, said electro-responsive device whenever edectively de-energized remaining in that condition and maintaining the brakes applied until reset, means for supplying energy to said circuit providing the engineers brake valve is in the service brakeapplying position, means for also supplying energy to said circuit provided a predetermined reduction in equalizing reservoir pressure has been made, and manually operable penalty inflicting means for resetting said device.

20. In an automatic train control system ofthe continuous inductive type in which the train is permitted to proceed in response to the flow of current flowing in the track rails directly ahead of the train, the combination with a normally energized electrically operable device adapted to cause an automatic application of the brakes of the train when de-energized, and means for independently maintaining said device energized including an auxiliary circuit for said device having two pairs of contacts in multiple, one of said pairs of contacts completing said auxiliary circuit when a brake application is being made manually and the other pair of said pairs of contacts completing said auxiliary circuit when an adequate brake application has been made and is maintained.

21. In an automatic train control system, the combination of a railway vehicle equipped with an air brake system of the type in which the brakes are applied upon a reduction of pressure in an equalizing reservoir, of an electrically operable device adapted to cause an automatic application of the brakes whenever fie-energized, means for maintaining said device energized if traffic conditions ahead are clear or if' the speed of the vehicle is not excessive, means for independently maintaining said device energized if the engineer initiates or completes and maintains an effective brake application until traffic conditions clear up or until the speed of the vehicle is no longer excessive, said electrically operable device being constructed so that if it is once (le-.energized it will remain de-energized until rel l Ni stored, and manually operable means effective only after a penalty has been inflicted upon the engineer for restoring said electrically operable device.

22. Car-carried apparatus for automatic train control systems comprising, means automatically operated to indicate clear, caution or danger in accordance With trafc conditions ahead, penalizing means of the type which if momentarily changed Will remain in the changed condition until restored to its previous condition, said penalizing means being biased to its effective condition but maintained in its normal inactive condition so long as and only When said first mentioned means is in its clear or caution condition but not when it is in its danger condition, and manually operable means for independently maintaining said penalizing means inactive, said manually operable means if operated restricting the progress of the train.

23. Car-carried apparatus for automatic train control systems of the type in which a suitable electro-responsive device on the car is continuously maintained energized by influences transmitted inductively in response to current flowing in the track rails ahead of the train under favorable trafiic conditions ahead comprising, a normally energized electrically operated brake control device connected to the usual air brake system in a manner to effect an application of the brakes when de-energized, a main circuit for energizing said device including a front contact of said device closed only When said device is in its energized condition, another circuit for energizing said device also including the front contact of said device, fluid pressure circuit closing means constructed to close its contacts when a brake application of a pre-determined value exists, contacts associated with the engineers brake valve of said air brake system closed when said brake valve is in a brake applying position, said another circuit including 1n multiple the contacts of said fluid pressure circuit closing means and the contacts associated with said engineers brake valve, Whereby said brake control device is not de-energized even though its main circuit has been opened by suitable train control means in the event the engineer is applying or has applied the brakes.

24. In an automatic train control system of the continuous inductive type; the combination With trackvvay apparatus for causing the flow of train control current in the track rails ahead of a train under favorable traffic conditions ahead of such train; and of car-carried apparatus comprising, infiuence receiving means including a relay energized when there is train control current flowing in the track rails ahead of the train, a normally energized electrically operated brake control device of the stick type which if decnergized effects a brake application and having an energizing circuit including in series a front contact of said device and a control contact governed by said relay, and two pairs of contacts each connected in multiple with said control contact one pair of Which are closed when the brakes are actually applied to a predetermined extent.

25. In an automatic train control system of the continuous inductive type; the combination with trackvvay apparatus for causing the flow of train control current in the track rails ahead of a train under favorable traffic conditions ahead of such train; and of car-carried apparatus comprising, influence receiving means including a relay energized when there is train control current flowing in thc track rails ahead of the train, a normally energized electrically operated brake control device of the stick type which if de-energized effects a brake application and having an energizing circuit including ,in series a front contact of said device and a control contact governed by said relay, and means for shunting said control contact when a brake application is being or has actually been made manuall In testimony whereof we here y aiix our signatures.

WINTHROP K. HOWE. CHARLES S. BUSHNELL. 

